Adds a TestTypeof bytecode to deal with comparisons of the form:
  typeof(object) === 'string';

Also adds support to Turbofan to perform these comparisons without
inserting checkpoints.

BUG=v8:4280,v8:5267

Change-Id: Ib5cc1c6816dfe70a4120838d8eada2fc0267750f
Reviewed-on: https://chromium-review.googlesource.com/454837Reviewed-by: Mythri Alle <mythria@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43832}